#!/bin/bash
#
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# TODO: set the upstream interface according to the environment variables of `script/setup`.
UPSTREAM_INTERFACE="eth0"
WPAN_INTERFACE="wpan0"

RADVD_CONF="/etc/radvd.conf"
LOG_TAG="dhcpcd.exit.hook:"

config_ra()
{
    logger "$LOG_TAG $reason start config radvd"

sudo tee "${RADVD_CONF}" > /dev/null <<EOF
interface ${WPAN_INTERFACE}
{
    AdvSendAdvert on;
    prefix ${1}/${2}
    {
        AdvOnLink on;
        AdvAutonomous on;
        AdvRouterAddr off;
        AdvPreferredLifetime ${3};
        AdvValidLifetime ${4};
    };
};
EOF
}


if [ ${interface} = ${UPSTREAM_INTERFACE} ]; then

    for var in $(env); do
        # Split the variable into name and value
        name="${var%%=*}"
        value="${var#*=}"
        logger -t "$LOG_TAG $reason sysenv: " "$name=$value"
    done

    case $reason in
        EXPIRE6 | STOP6 | RELEASE6 )
            # TODO: Handle multiple IA_PD prefixes (new_dhcp6_ia_pd{i}_prefix{j}, new_dhcp6_ia_pd{i}_prefix{j}_length, etc.)
            #       and deprecate old prefixes properly for each.  Currently, only one prefix is handled.)
            if [ -z "$old_dhcp6_ia_pd1_prefix1" ] || [ -z "$old_dhcp6_ia_pd1_prefix1_length" ]; then
                logger "$LOG_TAG WARNING: Missing DHCPv6 prefix information. Skipping radvd configuration."
            else
                config_ra $old_dhcp6_ia_pd1_prefix1 $old_dhcp6_ia_pd1_prefix1_length 0 0
                if systemctl is-active network.target; then
                    sudo systemctl reload-or-restart radvd
                fi
            fi
            ;;
    esac
fi
